This proposed research is designed to characterize the effects of cocaine on the 8 channel, automatically analyzed (period analysis) electroencephalogram (EEG) of the monkey, Macaca mulatta. The EEG samples will be of both spontaneous EEG and photically driven EEG over a 3-30 hertz range. The period analytic descriptors will be interpreted for individual channels and for cross correlation between homologous leads and for all areas recorded in various combinations. Changes in the EEG caused by acute cocaine administration will be utilized to delineate the relationships of chronic drug administration and free choice (self-administration) drug use in order to evaluate the development of tolerance to the effects of cocaine on the EEG and sleep profiles. The role of central catecholamines in the electroencephalographic effects of cocaine will be evaluated by manipulations of the catecholamine biosynthetic pathway with pharmacological tools. The results of these studies whould provide insights into the mechanism of action of cocaine, and suggest improved methods for treatment and prevention of cocaine abuse.